Spring check for loom parallel motion



Jan. 11, 1966 R. E. PAQUETTE 3,228,430

SPRING CHECK FOR LOOM PARALLEL MOTION Filed April 15, 1965 5 Sheets-Sheet 1 Fig.

Roland E Paquefle IN VE N TO K M403 BY Em Jan. 11, 1966 Filed April 15, 1963 Fig. 2

R. E. PAQU ETTE SPRING CHECK FOR LOOM PARALLEL MOTION 5 Sheets-Sheet 2 Roland E. Paqueffe 1N VEN TOR Jan. 11, 1966 R. E. PAQUETTE 3,228,430

SPRING CHECK FOR LOOM PARALLEL MOTION Filed April 15, 1963 5 Sheets-Sheet 5 Fig. 6 M52 7 Roland E Paquefle 1 N VE N TO K BY -Mm United States Patent 3,228,430 SPRING CHE'CK FOR LOGM PARALLEL MOTIGN Roland E. Paquette, Wolcott, Conn. (4 Brook Road, Hazardville, Conn.) Filed Apr. 15, 1963, Ser. No. 273,000 14 Claims. (Cl. 139-162) This invention comprises a novel and useful spring check for a loom parallel motion and more particularly pertains to a device for checking and cushioning the end of the strokes of the picker stick during its operation.

Conventional looms employ a picker stick pivoted at is lower end for oscillatory movement with an actuating means driven by the power source of the loom for urging the picker stick upon its picking stroke to thereby hurl the shuttle across the lay of the loom during the weaving operation, a spring means being relied upon to automatically return the picker stick to its original position in readiness for the next picking stroke. In view of the very heavy forces involved in effecting the picking stroke and in the rapid return of the picker stick to its original position, the above stopping of the movement of the stick at either extreme of its oscillation results in excessive wear upon the stick itself. In order to reduce the shocks and impacts resulting from the travel of the picker stick to the opposite extreme positions thereof, substantially all looms employ a check mechanism in the form of a check strap which loosely encircles the picker stick and provides a cushion or stop for each of its two extremes of movement. However, even with the use of a check strap to cushion the stopping of the stick at either end of its travel, the-re still arises excessively heavy shocks which rapidly wear the stick or the check strap so as to require their replacement. In fact, it is well known in the loom industry that substantially one-half of the labor required for the maintenance of a loom is employed in the maintaining of the picker stick and check strap mechanism in an efficient and operative condition. Inasmuch as the specific difficulties arising from the use of a conventional check strap mechanism for a picker stick are well known to those skilled in the art, a detailed description of the many such difficulties need not be here enumerated. As a result of these conditions, the expectant life of a picker stick check strap is not more than one month or two.

It is therefore the primary purpose of this invention to provide a checking mechanism for cushioning and stopping the picker stick at each extreme of its movement in such a manner as to greatly reduce the wear upon the stick itself, substantially obviate or very materially reduce the need for adjustment of the picker stick and check mechanism of a loom, and which will have a relatively long life expectancy of trouble-free operation.

It is a further purpose of the invention to provide a check mechanism which will completely eliminate the usual check strap mechanism of a picker stick and will replace it will a wear-resisting mechanism having a relatively long and trouble-free life expectancy.

Still another object of the invention is to provide a checking device which will replace the conventional check strap mechanism usually disposed at the upper end of the picker stick with a resilient retarding action applied to the picker stick at its lower end.

Yet another purpose of the invention is to provide a picker stick check mechanism which may be advantageously and compactly incorporated into the parallel motion of a loom.

A still further and more specific object of the invention is to provide a mechanical resiliently acting cushioning mechanism constituting a check mechanism for the parallel motion of a loom and which may be mounted upon and associated with one of the pivot connections of the parallel motion.

3,228,430 Patented Jan. 11, 1966 Another important object of the invention is to provide a check mechanism in accordance withthe foregoing objects which may be mounted upon or in place of the conventional crankpin by which one of the parallel motion components is pivoted to the picker stick holder of a loom.

A more specific object of the invention is to provide a mechanical check mechanism for a picker stick which shall obtain a variety of differently timed cushioning and checking actions upon the picker stick for resiliently opposing motion of the picker stick at different positions in its path of travel.

A further and more specific object of the invention is to provide a check mechanism in conformity with the preceding object which will selectively resiliently check and cushion the picker stick when it reaches the end of its picking stroke, will then cushion and effectively check the rebound of the stick after the completion of its picking stroke, and will thereafter further check and cushion the return of the picker stick from its rebound position to its original picking position in response to engagement by a returning shuttle.

A further important object of the invention in com pliance with the immediately preceding objects is to provide a check mechanism in accordance with the aforementioned objects which may be readily applied as an attachment to existing looms by merely replacing the conventional crankpin of the parallel motion with a slightly modified crankpin and the checking mechanism of this invention as applied thereto, and further wherein the strength of the checking action may be readily adjusted as may be desired.

And a final important object of the invention to be specifically enumerated herein resides in the provision of a check mechanism in compliance with the immediately preceding objects wherein the check mechanism may be readily adjusted in order to vary the angular positions at which the checking action is applied to a picker stick.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a fragmentary front elevational view of a portion of the end of a loom showing the picker stick and a loom parallel motion connected thereto and with the check mechanism of this invention applied thereto, the picker stick being shown in full lines in its initial position in readiness for the picking stroke and in dotted lines at the end of its picking stroke;

FIGURE 2 is a vertical transverse sectional view of the parallel motion taken upon an enlarged scale substantially upon the plane indicated by the section line 22 of FIGURE 1;

FIGURE 3 is a horizontal sectional detail view of the parallel motion taken upon an enlarged scale substantially upon the plane indicated by the broken section line 33 of FIGURE 1;

FIGURE 4 is a further detail view taken upon an enlarged scale substantially upon the plane indicated by the section line 44 of FIGURE 2 and showing in elevation one of the two check plates of the mechanism and an actuating element of the checking mechanism in association with said plates;

FIGURE 5 is a view taken upon the plane indicated by the section line 55 and showing in elevation the complementary cam check plate of the checking mechanism;

FIGURE 6 is a further detail view in vertical transverse section taken substantially upon the plane indicated by the section line 66 of FIGURE 4;

FIGURE 7 is a detail view partly in vertical longitudinal section and partly in elevation of the check mechanism showing the manner in which it is applied to a pivot connection of a loom parallel motion;

FIGURE 8 is an exploded perspective view of the elements forming the check mechanism of this invention;

FIGURES 9-11 are diagrammatic views in horizontal section showing the operation of a conventional picker stick and check strap therefor in accordance with prior practice;

FIGURE 12 is a further detail view partly in elevation and partly in vertical section of the lower portion of the picker stick and the spring return means therefor;

FIGURE 13 is a diagrammatic view showing the separate and distinct checking or cushioning actions of the check mechanism of this invention during a complete picking cycle of the picker stick; and

FIGURE 14 is a perspective view of a protective housing which may be employed to enclose the check mechanism of the invention.

Reference is made first to FIGURE 1 which shows a portion of one end of a loom to which the check mechanism of this invention has been applied. The illustrated loom is the well known Draper loom of various types such as the models E, XK, X, X2, X-3, XL, XD, K, XP and XP-2. However, with changes in dimensions and in the adaptation of the mounting of the check mechanism to existing loom structure, the check mechanism of the invention may be readily applied to other conventional types of looms such as the Crompton- Knowles and the like.

Referring now specifically to FIGURE 1, it will be observed that a portion of the frame of a loom is indicated by the numeral there being mounted upon this frame the usual arms 12 by means of which the reed lay 14 having a conventional shuttle box 16 is mounted. Indicated diagrammatically at 18 is another portion of the loom frame 10 having a buffer 20 which is adapted to be engaged by and to positively stop the picker stick 22 when the latter is at the end of its picking stroke as indicated by dotted lines at 24. The picker stick itself is connected to the parallel motion indicated generally by the numeral 30 so that as the picker stick is operated by the conventional picker actuating means of a loom, not shown, by means of a connecting link 32 and arm 34, it will be reciprocated by its pivoted lower extremity between the full line position shown in FIGURE 1 which is the initial or picking position and the dotted line position shown at 24 which is the end of the picking stroke.

As will be understood, the conventional parallel motion 30 consists of a plurality of pivotal connections between various connected elements or components such as to afford a fairly straight line motion imparted to the shuttle, not shown, when the latter is engaged by the end of the picker stick 22 and the picker stick is actuated upon its picking stroke from left-to-right as viewed in FIG- URE l.

The picker stick is returned from the completion of its picking stroke back to its initial position by a resilient return means including a strap 36 secured to the lower end of the picker stick, see also FIGURE 12, and which strap in turn is secured to a spring 38. Inasmuch as the details of the means for actuating the picker stick on its picking stroke, the resilient return means and the parallel motion are all well known a further description thereof is deemed to be unnecessary. It sufiices for an understanding of one manner of applying the principles of this invention to note that the pivot connection by which the parallel motion is connected to the picker stick includes a crankshaft. In accordance with this invention, the conventional crankshaft is replaced by a slightly modified crankshaft 40, see FIGURE 6, having a first crank pin 42 journaled in the picker stick holder 43 and a second crank pin 46 which is somewhat longer than the conventional corres onding crank pin for a purpose to be subsequently apparent and is journaled in the parallel motion component 44.

It should be understood at this point that the check mechanism indicated generally by the numeral 50 and which forms the subject matter of this invention may be operatively associated with any pivotal connection of any of the mechanisms which is attached to a picker stick in order to provide a resiliently yieldable retarding action opposing pivoting movement of that pivotal connection. Further, the checking device or check mechanism may be of various constructions it being merely essential that there shall be produced a controlled resisting action upon such pivotal movement at the associated pivot joint.

An essential novel feature and concept of this invention resides in the locating of the checking mechanism at the lower end of the picker stick as contrasted with the location of the conventional check strap at the upper portion thereof, and further in locating the check mechanism in connection with the parallel motion of the picker stick. In the accompanying drawings there is disclosed in order to illustrate one satisfactory manner of carrying out and applying the principles of this invention to a picker stick construction of a loom, a check mechanism which is applied to the crankpin connecting the parallel motion to the picker stick of a loom.

Referring now especially to FIGURE 8 in conjunction with FIGURES 6 and 7, it will be observed that the check mechanism 50 comprises a number of elements which are all mounted upon and supported by the crank pin 46 of the crankshaft pivot 40.

The essential components of the check mechanism 50 consist of a pair of cooperating check plates 52 and 54 having opposed faces or thrust surfaces 56 and 58 respectively together with an actuating element in the form of a pin 60 which is received in a transverse slot 62 in the elongated crank pin 46. The pin extends diametrically of the crank pin 46 and lies between and is engaged by the two opposed surfaces 56 and 58 of the two check plates. One of these plates comprises a body which may be considered as the mounting plate of the device is provided with a pair of parallel brackets 64 and 66 projecting laterally therefrom and each provided with a fastening screw 68. As will be observed especially from FIGURE 7, the two brackets are adapted to straddle or embrace therebetween the parallel motion member or component 44 and to be retained thereon in rotationally adjusted position about the axis of the crank pin 46 by means of the adjusting screws 68 which engage in recesses as at 70 in the opposite sides of the parallel motion member 44. By means of the brackets or lugs 64 and 66 the mounting plate 56 of the check assembly is adjustably but fixedly mounted upon the member 44 in laterally projecting relation therefrom.

Each of the plates 52 and 54 is provided with an aperture 72 and 74 therethrough by which the plates pivotally receive therethrough the crank pin 46. The plates are thus coaxial with each other and with the axis of the crank pin 46 but are spaced axially from each other by the interposition of the transverse pin 60 therebetween. The plate 52 is stationary with respect to the parallel motion component 44, it being mounted fixedly but adjustably upon the member 44. Projecting axially from the plate 52 is a pair of guide pins each indicated by the numeral 76, and detachably received in sockets 78 in the plate 52 and being retained therein as by setscrews 80. Corresponding bores 82 in the other plate 54 mount the latter upon the guide pin 76 for axial sliding movement upon these pins and upon the crank pin 46.

The outer end of the crank pin 46 is provided with an internally threaded bore 84 which intersects the bore 62. The bore 84 is diametrically reduced at its intersection with the bore 62 and this reduced portion receives therein the setscrew 86 by which the pin 60 is releasably secured in the transverse bore 62 A spring adjusting screw 88 is engaged in the threaded bore 84 and by means Q a washer 90 adjustably retains a spring assembly 92 which engages and yieldingly urges the plate 54 axially towards the other plate 52 and against the pin 60 interposed therebetween.

Referring to FIGURE 8 it will be observed that the spring assembly 92 consists of a series of resilient disks or washers such as the Belleville washer, there being reversely disposed washers as at 94 and 96 in series. Obviously, by adjusting the compression of these washers against the plate 54 through the use of the adjusting and retaining screw 88, a varied resilient force may be applied urging the plates together and compressively embracing the pin 6% therebetween.

At least one of these plates, as for example the plate 54, has its face which is opposed to the other plate formed to provide cam surfaces. Thus, there are provided dwell port-ions or recessed portions as at 98 and raised or inclined cam portions as at 100. In some instances, both of the plates 52 and 54 may be provided with the opposed cam surfaces, although it will generally be found that one such surface is suflicient.

Referring now especially to FIGURE 5 it will be observed that the cam surface 58 of the plate 54 has a pair of diametrically opposed circumferentially extending flat, raised surfaces 100 with the flat depressions, dwell or lowered portions 98 of the cam 58 being disposed therebetween. Each of the dwell portions 98 is provided with an inclined cam surface 102 at its opposite ends where it joins the adjacent cam surface 100. There are thus provided four ramps or cam surfaces 102 for the two cam recesses 98 for a purpose to be subsequently set forth.

Shown in FIGURE 14 is a sleeve or housing 104 adapted to embrace as shown in FIGURE 7 the pair of check plates 52 and 54. At what may be termed its inner end, the sleeve is provided with a diametrically reduced sleeve extension 106 provided with setscrews 108 and slots 11% by which it is adapted to embrace the plate 52 and the mounting brackets or lugs 64, 66 thereon and to be removably secured thereto while enclosing in a protective manner the movable elements of the check mechanism.

For an understanding of the method which is performed by this invention attention is now directed to the diagrammatic views of FIGURES 9-11 which relate to the operation of a conventional check strap of a picker stick. The check strap, whether of the endless or the overlapping type is indicated at 112 being mounted in a conventional manner upon the lay of the loom below the shuttle box. This strap frictionally slides through the frictional guide members 114 and provides a loop in which is received and within which moves the conventional picker stick 22. FIGURE 9 shows the position of the picker stick in its rest position in readiness for the picking stroke. It will be noted that the strap has shifted to its maximum extent to the left of this figure so as to accommodate and retain the picker stick against the action of the return spring 36, 38 of FIGURE 12. When now the picking mechanism of the loom has been actuated, the picker stick is thrown violently to the right to the position shown in FIGURE until its action to the right is checked by engagement of the picker stick as shown at 24 in FIGURE 1 with the buffer or abutment 20. At this time, the loop formed by the check strap 112 has shifted towards the right and the frictional resistance offered by the members 114 during such shifting has imposed a frictional drag upon the stick which cushions it prior to its final stopping by its impact against the abutment 20. The position of FIGURE 10 is thus the position assumed by the picker stick in its completion of the picking stroke. When the picker stick reaches the position of FIGURE 10 and strikes the abutment 20, under the action of the return spring 36 it will rebound and move towards the left towards its original position. However, the energy imparted to it by the picking mechanism and which drove it to the right has been largely dissipated by its engagement with the buffer 20 and the checking action of the check strap so that the rebound energy will be dissipated before the picker stick and the check strap resume their original positions. Thus, as shown in FIGURE 11, the picker stick has reached its rebound position which is short of the picking position of FIGURE 9. In this rebound position it will be noted that the check strap still has a portion of its loop at the right untensioned and that action of the members 114 and their frictional drag has halted movement of the picker stick during its rebound to a position which is short of its final or initial position. In the rebound posit-ion, the picker stick remains until the returning shuttle thrown back across the loom from the picker at the other side thereof strikes the picker stick and drives it towards the left against the resistance of the check strap until the picker stick and check strap again assume the position of FIGURE 9 in readiness for the next picking operation.

The check mechanism of this invention is designed to perform these same three functions and checking actions, but to do so by a purely mechanical mechanism thereby eliminating the irregularity of operation which arises from the use of the frictional engagement of the check strap with the members 114.

The operaion of the check mechanism and the method performed thereby in the checking of the picker stick will now be considered in connection with the diagrammatic view of FIGURE 13 in conjunction with the previously described operation of the conventional check mechanism discussed in connection with FIGURES 9411.

In the diagrammatic view of FIGURE 13 it will be noted that the cam recess 98 is shown disposed between the two cam surfaces by the ramps or cam surfaces 102. Represented at A is the position of the actuating element 60 or transverse pin in the initial or picking position shown in solid lines in FIGURE 1. At this time, the pin 60 rests upon the flat raised surface 100 and is retained thereagainst under the tension of the spring assembly 92 in which position it retains stored energy in the spring assembly. When the picking stroke is given to the picker stick by the picking mechanism of the loom, the picker stick is thrown to the right until it reaches the end of its picking position as shown in dotted lines at 24 in FIGURE 1. The pivot connection to which this check mechanism is connected thus likewise has a pivoting movement which causes the actuator element or transverse pin 60 to travel from the raised surface 100, down the cam surface 1H2, across the flat recess 98 and up the cam surface 192 until it again rides upon the raised surface 100 at the position B. It will be observed that when it descended the cam surface 102 from the position A, and moved into the recess 98, the compression of the spring assembly 92 was released so that there was no checking action for the oscillation of the transverse pin during the travel across the surface 98. However, towards the end of the picking stroke, the actuator element or transverse pin 60 ascended the cam slope 102 and emerged upon the raised surface 100 at the position B, the spring assembly 92 being again compressed and a resilient retarding action Was thus applied opposing resiliently further pivoting movement at the associated pivot connection, in this case, the crankpin. Consequently, before the picker stick struck the abutment 20 in the position 24 of FIGURE 1, its motion was materially checked and its energy stored in the spring assembly by the travel of the transverse pin 60 up the cam surface 102 to the position B. The checking action thus afforded by this device was identical with that afforded by the conventional check strap when moving from the position of FIGURE 9 to that of FIGURE 10 so far as the overall results and timing are concerned. It will be evident, however, that the kinetic energy of the picker stick was cyclically absorbed by the spring assembly and then returned to the picker stick.

Upon the rebound of the picker stick from its position at the end of the picking stroke, the picker again travels towards the position A. However, as above pointed out, the rebound energy in the stick is less than the energy upon its picking stroke and therefore the element 60 is unable to fully ascend the cam surface 102 to the position A. Consequently, it ascends this slope to a varying degree and then under the energy of the spring assembly 92 moves back upon the recess 93. This is the rebound position shown at C in FIGURE 13. It remains in this position, free of resilient checking action since the member 60 is upon the recess 98 of the surface 58 of the plate, until the picker stick is struck by the return of the shuttle. This is the position corresponding to that shown in FIGURE 11 with a conventional check strap mechanism. When the shuttle strikes the picker stick, its impact causes the transverse pin 60 to ascend the ramp 102 and then ride upon the raised surface 100 at the position A where the check plates are again under and places tension upon the spring assembly 92 and are thus frictionally retained in the initial position in readiness for the next picking operation.

Inasmuch as the position of the transverse pin 60 comprising the actuator element of the check mechanism is fixed with respect to the oscillating crank pin 46, it oscillates throughout a fixed path of oscillatory travel. Consequently, in order to vary or adjust the position of the cam surfaces with respect to the actuator element or pin 60, it is necessary to rotationally adjust the check plates 52 and 54 about the axis of the crank pin 46 and thus the axis of rotation of the pin 60. It is for this purpose that the previously described mounting brackets 64 and their fastening bolts 68 are provided. Inasmuch as the two plates 52 and 54 are in effect journaled as a unit upon the oscillating crank pin 46, tightening one fastener and loosening the other fastener 68 will cause a slight rocking action or rotational adjustment of the plate 52 and its brackets 64 and 66 with respect to the member 44 of the loom parallel motion. Inasmuch as the two plates are maintained against relative rotation by the guide pin 76, they will both thus be rotatably adjusted as a unit.

On the other hand, although the mounting plate 52 is fixed with respect to the parallel motion member 44 which constitutes its support member, the other cheek plate 54 is axially movable towards and from the plate 52 but is restrained against rotational movement with respect thereto. The frictional gripping action of the two plates upon the oscillating pin 66 disposed therebetween thus resiliently retards oscillation of this pin and of the associated crankshaft 40 to an extent which is proportional to the resilient force applied. This force is readily adjustable through the fastener 83 and its affect upon the compression loaded spring assembly 92.

It is important to observe that the adjustable spring pressure is at a maximum when the plates are separated to their greatest extent, as when the actuator pin 60 rests upon the raised surfaces 100 and is at a minimum which may but does not necessarily completely free the pin from any resilient load when the pin rides in the recess 98. This adjustment can be varied in order to adapt the device to the specific operating characteristics of the picking mechanism of a. particular loom.

Obviously, the device can be readily applied to the existing structures of conventional looms merely by replacing the crankpin 40 with the crankpin of this invention and mounting the rest of the components of the check mechanism upon the replacement crankpin. On the other hand, the device can be installed in any loom during its initial assembly at a factory.

It is desired to point out that the replacement crankpin differs from a conventional or original crankpin only as to the length of the crank pin 46 which is slightly longer than the original crank pin of the conventional crankshaft, the presence of the diametrical bore 62 therein, and the presence of the intersecting threaded bore 84.

When wear occurs the device. can be readily removed or disassembled and the worn part readily replaced. However, inasmuch as the wear occurs only between the check plates 52, 54 and the actuator element or pin 60, it is evident that this check. mechanism has a relatively vastly longer period of useful life than does the conventional check strap. Whereas the latter usually requires replacement after not more than a month or two of operation, the check mechanism of this invention may be reasonably expected to have a useful life of many months or even years.

It is also desired to point out that due to its location and the mechanical advantage afforded by the cooperative relationship between the oscillating transverse pin 60 and the axial cam surface 58 that a relatively small force on the compression spring assembly 92 is effective to produce the desired cushioning and checking action upon the picker stick, which action would require a much larger force at the location of the conventional check strap assembly.

Although a series of Belleville washers 92 has been illustrated in the drawings as a preferred type of spring means, it will be understood that the invention comprehends the use of various other types of resilient means for imparting a resilient thrust to the pin 60 and the surfaces and 102, it being necessary only that the pin and cam be spring loaded when the pin rides upon the cam rises and be unloaded when the pin is on the cam recesses.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A loom picker stick parallel motion connected to a picker stick and including a plurality of pivotally connected relatively movable components, a resilient check mechanism connected to a pair of said components and resiliently opposing relative angular movement therebetween, said check mechanism including connecting means pivotally connecting said pair of components and including a pivot pin rotatably journaled in a first component, an actuator secured to said pivot pin against rotation relative thereto, a member mounted on said pivot pin for sliding movement relative thereto, a pair of coaxial opposed thrust surfaces on opposite sides of and embracing said actuator therebetween, one thrust surface being carried by said member and the other being carried by and fixed relative to said first component, means preventing relative rotation between said thrust surfaces but enabling relative axia-l movement thereof toward and from each other, at least one of said surfaces having axial cam elements engaging said actuator and operable by rotary movement of the latter to effect axial movement of said member, resilient means engaging said member and yieldingly urging the latter against said actuator and thereby opposing, by engagement of said cam elements with said actuator, relative rotation of said pivot pin relative to said first component, said cam elements being positioned to increase the energy content of said resilient means and thereby exert increased force opposing rotation of said pivot pin on said first component during predetermined portions only of movement of said parallel motion.

2. The combination of claim 1 wherein said resilient means together with said member and said actuator constitute means for absorbing and storing by compression of said resilient means a portion of the kinetic energy of said parallel motion at the terminal positions of the picking stroke and the return stroke of said parallel motion and return the stored portion of energy of said resilient means to said parallel motion as kinetic energy as the parallel motion moves from said terminal positions upon the return stroke and picking stroke.

3. The combination of claim 1 wherein said resilient means together with said member and said actuator constitute means for converting a portion of the kinetic energy of said parallel motion at each extreme position of its movement substantially entirely into potential energy by compressing said resilient means and for transferring said potential energy stored in said resilient means into kinetic energy in said parallel motion when the latter leaves said extreme positions upon the succeeding strokes.

4. The combination of claim 1 wherein said resilient means together with said member and said actuator comprise means for converting a portion of the kinetic energy of said parallel motion substantially without friction loss into potential energy by compressing said resilient means as said parallel motion approaches an extreme position of its movement, the departure of said parallel motion from said one extreme position upon its reverse stroke triggering the release of said stored potential energy from said a resilient means and returning the stored potential energy as kinetic energy to said parallel motion.

5. The combination of claim 1 including a body secured to and carried by said first component, said other thrust surface being disposed upon said body.

6. The combination of claim 5 wherein said body carries said relative rotation preventing means.

7. The combination of claim 1 wherein said member and first component include a pair of check plates each carrying one of said thrust surfaces, the second of said check plates carrying said other thrust surface and being fixedly secured to said first component, said relative rotation preventing means being carried by said second check plate and comprising guide pins slidably received in guide bores in the first of said check plates.

8. The combination of claim 7 wherein said resilient means comprises a spring assembly engaging said pivot pin and said first check plate and urging the latter against said actuator.

9. The combination of claim 1 wherein said member and first component include a pair of check plates each carrying one of said thrust surfaces, the second of said check plates carrying said other thrust surface and being fixedly secured to said first component, said actuator comprising a pin secured to and extending diametrically from opposite sides of said pivot pin and engaging both of said thrust surfaces and said axial cam elements.

10. The combination of claim 1 wherein said actuator comprises a pin secured to and extending diametrically from opposite sides of said pivot pin and engaging both of said thrust surfaces and said axial cam elements.

11. The combination of claim 1 wherein said member and first component include a pair of check plates each carrying one of said thrust surfaces, the second of said check plates carrying said other thrust surface and being fixedly secured to said first component, said relative rotation preventing means being carried by said second check plate and comprising guide means slidably received in guide bores in the first check plate, means for adjusting said check plates rotationally about the axis of said pivot pin and about said actuator thereby varying the timed relation of the checking action relative to the picker stick movement.

12. The combination of claim 1 wherein the engaging portions of said actuator and thrust surfaces are wholly metallic.

13. A loom picker stick parallel motion connected to a picker stick and including a plurality of pivotally connected relatively movable components, a resilient check mechanism connected to a pair of said components and resiliently opposing relative angular movement therebetween, said check mechanism including connecting means pivotally connecting said pair of components and including a pivot pin rotatably journaled in a first component, an actuator secured to said pivot pin against rotation relative thereto, a member mounted on said pivot pin for sliding movement relative thereto, said member having a thrust surface engaging said actuator, means preventing relative rotation between said thrust surface and said first component but enabling relative axial movement thereof, said member being relatively rotatable and axially slidable upon said pivot pin, said thrust surface having axial cam elements engaging said actuator and operable by rotary movement of the latter to effect axial movement of said member, resilient means engaging said member and yieldingly urging its thrust surface against said actuator and thereby opposing, by engagement of said cam elements with said actuator, relative rotation of said pivot pin relative to said first component, said cam elements being positioned to increase the energy content of said resilient means and thereby exert increased force opposing rotation of said pivot pin on said first component during predetermined portions only of movement of said parallel motion.

14. A loom picker stick parallel motion including a plurality of pivotally connected relatively movable components and resilient check means connected to a pair of said components for alternately resiliently opposing and subsequently resiliently consisting relative angular movement therebetween at the terminal portions only of said relative angular movement, said check means comprising; means pivotally connecting said pair of components and including a pivot pin rotatably journaled in a first component, an actuator secured to said pivot pin against rotation relative thereto, a member including a cam surface engaging said actuator, said member being secured to one of said components and limited to movement relative thereto in one direction, resilient means engaging said member and yieldingly urging it to movement in said one direction, said cam surface having at least two cam elements thereon including a central dwell element disposed between a pair of side cam elements successively engaged by said actuator and said member being operated by relative movement of said pivot pin with respect to said component to selectively vary the energy content of said resilient means, said central dwell element when engaged by said actuator retaining a minimum energy content in said resilient means, said side cam elements imparting a maximum energy content to said re silient means upon predetermined positions of said parallel motion components, said cam elements and actuator later releasing the energy content stored in said resilient means to aid rotation of said pivot pin during other predetermined positions.

Reterences Cited by the Examiner UNITED STATES PATENTS 925,559 6/1909 Brown 188-130 X 951,376 3/1910 Merritt 188-130 X 1,135,909 4/1915 Malloy 188-130 1,279,314 9/1918 Flowers et al. 139-162 1,428,739 9/1922 Youngquist 139-165 X 2,529,696 11/1950 Hufferd 139-149 X 2,557,023 6/1951 Ashton et al. 139-164 FOREIGN PATENTS 862,988 12/1940 France.

DONALD W. PARKER, Primary Examiner.

RUSSELL C. MADER, Examiner. 

1. A LOOM PICKER STICK PARALLEL MOTION CONNECTED TO A PICKER STICK AND INCLUDING A PLURALITY OF PIVOTALLY CONNECTED RELATIVELY MOVABLE COMPONENTS, A RESILIENT CHECK MECHANISM CONNECTED TO A PAIR OF SAID COMPONENTS AND RESILIENTLY OPPOSING RELATIVE ANGULAR MOVEMENT THEREBETWEEN, SAID CHECK MECHANISM INCLUDING CONNECTING MEANS PIVOTALLY CONNECTING SAID PAIR OF COMPONENTS AND INCLUDING A PIVOT PIN ROTATABLY JOURNALED IN A FIRST COMPONENT, AN ACTUATOR SECURED TO SAID PIVOT PIN AGAINST ROTATION RELATIVE THERETO, A MEMBER MOUNTED ON SAID PIVOT PIN FOR SLIDING MOVEMENT RELATIVE THERETO, A PAIR OF COAXIAL OPPOSED THRUST SURFACES ON OPPOSITE SIDES OF AND EMBRACING SAID ACTUATOR THEREBETWEEN, ONE THRUST SURFACE BEING CARRIED BY SAID MEMBER AND THE OTHER BEING CARRIED BY AND FIXED RELATIVE TO SAID FIRST COMPONENT, MEANS PREVENTING RELATIVE ROTATION BETWEEN SAID THRUST SURFACES BUT ENABLING RELATIVE AXIAL MOVEMENT THEREOF TOWARD AND FROM EACH OTHER, AT LEAST ONE OF SAID SURFACES HAVING AXIAL CAM ELEMENTS ENGAGING SAID ACTUATOR AND OPERABLE BY ROTARY MOVEMENT OF THE LATTER TO EFFECT AXIAL MOVEMENT OF SAID MEMBER, RESILIENT MEANS ENGAGING SAID MEMBER AND YIELDINGLY URGING THE LATTER AGAINST SAID ACTUATOR AND THEREBY OPPOSING, BY ENGAGEMENT OF SAID CAM ELEMENTS WITH SAID ACTUATOR, RELATIVE ROTATION OF SAID PIVOT PIN RELATIVE TO SAID FIRST COMPONENT, SAID CAM ELEMENT BEING POSITIONED TO INCREASE THE ENERGY CONTENT OF SAID RESILIENT MEANS AND THEREBY EXERT INCREASED FORCE OPPOSING ROTATION OF SAID PIVOT PIN ON SAID FIRST COMPONENT DURING PREDETERMINED PORTIONS ONLY OF MOVEMENT OF SAID PARALLEL MOTION. 